- Specific space heat demand: 14.3 kWh/(m2a), calculated in PHPP;
- Specific primary energy demand (primary energy for heating, hot water and household electricity): 102 kWh/(m2a), calculated in PHPP;
- Energy conservation by solar electricity: 11 kWh/(m2a);
- Heating load: 17 W/m2
The residential building is designed according to the Passivhaus standard by Passivehaus Institut – Dr. Wolfgang Feist in Darmstadt, Germany and the PHPP methodic (Passive House Planning Package).
- The main requirements of the standard are observed:
Specific energy consumption for heating and cooling is less than 15KWh/m2 per year.
- Total primary energy demand (primary energy for heating, hot water and household electricity) is less than 120 kWh/m² annually.
- Airtightness is less than 0.6h-1
The PHPP calculations are part of the project documentation. When built and all tests and required documents for the house are ready, the house will be certified as passive in accordance with the Passivhaus Institut requirements.
The residential building “Type B” is an independent single family house with garage. It represents a compact volume with roof orientation towards the south direction. It has two main floors and a basement, partially under the terrain. In the basement are placed: garage for two vehicles, technical room, laundry and drying-room, cellar and a corridor in front of the internal staircase.
On the ground floor are designed: entrance hall, toilet room, entry, living-room and dining-room, kitchen, master bedroom zone which consists of a bedroom, bathroom and a closet. In front of the living-room and the dining-room there is a large south terrace on the terrain.
On the first floor there are 3 bedrooms with independent closets and bathrooms. The first floor foyer represents a family gym.
The staircase to the ground floor is closed into an independent glazed volume for a better heat and sound insulation. Two of the bedrooms have an outlet to a small covered south terrace. The two bedrooms on the east side have a partly double glazed façade and between their two halves there is air over the living-room, with which the natural convection is ensured and controlled.
This residential building is oriented with its long facades flatly towards the north-south direction. The glazed south façade is the main, towards which all living premises are oriented. All service rooms as well as the staircase are north oriented. The east, the west and the north facades are almost all solid with small openings for windows and doors.
The building construction is made of reinforced concrete frame of foundations, pillars, beams, slabs and roof with ant seismic frame structure. The outer walls are light factory prefabricated panels suspended externally over the concrete frame. They are made of wood frame, filled with 35 cm glass wool, boarding on both sides with OSB plates, interior boarding and exterior ventilated wooden cladding. The roof, the front fascias and the finishing of the eaves are covered with zinc sheets. The internal walls are made of gypsum board. In the living premises and the bathrooms the suspended ceilings are also made of gypsum board. The flooring is made of stone in the living-room, the dining-room, the entrance hall and the kitchenette and it is made of laminated parquet with natural finish in the closets and the bedrooms; terracotta is used for the bathrooms.
The flooring on the external terraces is horizontal, made of larch boards with open gaps. In the living-room, the dining-room and the bathrooms a Rehau floor heating system will be used. The south glazed façade is suspended with special triple glazing, REHAU facade system (Polytec 50 PHZ), certified for passive houses use with total Ug=0.768W/m2K for the whole façade with aluminium covering from outside. At the south side in the section of the double facade a roof glazing is designed from the same system with ventilation valves. At the south slope from west there will be integrated 4 photovoltaic modules and 3 solar collectors. The external door of the main entrance will be a REHAU product, certified for passive house use with U=0.695W/m2K. The garage door is made of steel with additional thermal insulation.
The garden design provides abundant planting with high and low vegetation. The planting has an additional insulation function between the houses in the complex. It will contribute to the high level of habitation comfort and aesthetics.
House Type B has a bold, contemporary and nontraditional appearance which is a straight result of the passive architecture, subject to the concept of maximum solar gains in the energy balance of the house. It has a provocative, yet cozy appearance. The building itself together with the abundant planting and garden design give a very high level of habitation comfort and aesthetics in unison with the nature and its preservation.
Measure for energy consumption decrease and use of renewable energy sources:
- ompact volume of the building;
- Non-admission of thermal bridges in the outer envelope of the house;
- Division of the premises in temperature zones. The garage is insulated from the other premises of the house and all thermal bridges from the garage to the heated premises are avoided.
- High values of insulation of the house;
- Walls with U=0.110W/m2K with active thermal insulation of 30 cm glass wool;
- Roof with U=0.098W/m2K with external thermal insulation of 40 cm glass wool;
- Slab on level ±0.00 over the non heated garage with U=0.117W/m2K with active thermal insulation of 25 cm glass wool;
- External wall of the heated premises of the basement towards the ground with U=0.086W/m2K with active thermal insulation of 30 cm glass wool;
- Slab on level -2.80 over the ground with U=0.187W/m2K with 20cm XPS insulation.
- High level of air tightness of the building. With the use of light prefabricated wall panels the air tightness is achieved by the climate membrane „ISOVER KM Vario” put internally under the interior finishing. An air tightness test will be conducted with a blower door fan sealed into the exterior doorway. During this test it is necessary that the air tightness level is measured below 0.6h-1Pa. The test will be done by a certified company and the good result is of highest importance for the certification of the building.
- “Trombe-Michel wall” behind the south suspended façade. This is a massive visible beam made by reinforced concrete, located behind the glazed façade. This beam is warmed up directly by solar rays in winter, accumulates the heat and then it slowly gives this heat in the interior during the day and night.
- Thermal mass. The presence of sufficient thermal mass in the interior of the house is important for least daily fluctuation of the temperature. By these means the thermal comfort is of highest level.
- Design of different schemes of air exchange in the volume of the living-room. The two big outlets at the top behind the glazed façade allow ascending flux of the warm air towards the glazed roof. The glazed shutters hidden in the suspended ceiling on level +3.40 can open or close this volume over the living-room. In such a manner they either allow or restrain the circular air flux upwards to the air duct over the ceiling of the middle bedroom, from there towards the ceiling of the staircase, from there vertically through the staircase and at the end again to the living room. By this the air in the south and the north parts of the house is united. Thereby together with the possibility to open the south façade and emitting the warm air through the valves there is a possibility to control the convection by different schemes of air exchange during a winter day with or without solar shine and also in summer.
- Windows with high level of insulation with an average U=0.768 for all windows. The façade windows on the east, west and north are Rehau system for passive houses „Clima design” with Uf – frame = 0.71W/m2K. For the suspended south façade and the roof glazing a system „Polytec 50 PHZ – Rehau” with Uf-horizontal frame= 0.76W/m2K and Uf-vertical frame= 0.74W/m2K certified for passive houses will be used. A triple-pane insulated glazing with U=0.6W/m2K will be used.
- External sun protection against overheating of the house in summer; The south façade is completely protected using awnings and external aluminum blinds in front of the suspended façade. The roof glazing is also protected externally using an awning along the slope. The sun protection will be actively controlled with an electronic system device with gauges, monitoring the solar shining, the wind speed and also the need of letting the solar rays for heating the interior in winter.
- Controlled ventilation of the house. Fresh air is supplied to every room in the house and the polluted air is removed constantly out of the kitchen, the toilets and the bathrooms. This averts the need to open the windows for ventilation in cold winter and hot summer and also there will be always fresh air in the living premises covering all hygienic requirements.
- Heat recovery ventilation system with a heat recovery rate of over 80%. The heat recovery ventilation employs a counter-flow heat exchanger between the inbound and outbound air flow. The heat recovery ventilation provides fresh air and improved climate control, while also saving energy by reducing the heating (or cooling) requirements.
- Pre-heating/cooling of the fresh air with an air ground heat exchanger around the house – a Rehau system „Awadukt thermo”. This pre-conditioning of the house gains a significant amount of renewable geothermal energy and thus eliminates the need for air conditioning of the house. Moreover the incoming air always passes through a primary filter situated in the house yard in the middle of abundant planting.
- Solar collectors for hot water. There will be 3 integrated in one system flat collectors with a 400 liters boiler which will satisfy almost all needs of the house for hot water all year round.
- Photovoltaic panels for electricity. On the roof 4 integrated modules with total capacity 1.08KW will be installed, which will recharge the accumulators and via inverter will help the electrical system of the house during the night.
- Reservoir collection of the rain waters from the roof of the house and their use in the flushing cisterns. A reservoir with a 5m3 capacity will be provided to which after pre-filtering the rain waters will get from the main roof of the building. After that these waters will be pumped out through a device in the laundry room and from there they will be distributed to all flushing cisterns independently from the main water-pipes. This system has the possibility to switch over to the main water-conduit when there are insufficient rainfalls during the year. This system will lead to a significant savings of drinking water during the year.
- Energy saving household appliances and lighting. All lighting fixtures will be energy saving or LED. The washing machine and the dishwashing machine will be using hot water produced by the solar collectors. The cooking will be on a gas cooker.
- The needed energy for heating and hot water will be added by a gas appliance located in the technical room in the basement.
Sq. Area: 446 м2
Designer: Studio APXE
Design Team: arch. Georgi Nikolov, Boshko Takov
Investor: Smart Houses Ltd.